Published PCT Application WO 97/01984 (PCT/IL96/0027) describes a method for effecting biofeedback regulation of at least one physiological variable characteristic of a subject's emotional state, including the steps of monitoring at least one speech parameter characteristic of the subject emotional state so as to produce an indication signal, and using the indication signal to provide the subject with an indication of the at least one physiological variable. A system permits the method to be carried out in a stand-alone mode or via telephone line in which case the indication signal may be derived at a location remote from the subject. Information related to the subject's emotional state can be conveyed vocally to a remote party or textually through the Internet, and then processed as required.
Published PCT Application WO 95/20216 (PCT/US95/00493) discloses a method and apparatus for indicating the emotional state of a person by the person's speech by: detecting speech waves of the person; subjecting the detected speech waves to backward and forward inverse filtering operation to obtain residual signals; cross-correlating the residual signals to produce a cross-correlated output; integrating with maximum overlapping the backward and forward residual signal, thereby achieving an estimation of the glottal wave; and processing the above glottal wave estimation to provide an indication of the emotional state of the speaker.
Published European Patent Application No. 94850185.3 (Publication No. 06 664 537 A2) describes a method and arrangement for determining stresses in a spoken sequence. From a sequence recognized in the spoken speech, a model of the speech is created. By comparing the spoken sequence with the modeled speech, a difference between them is obtained.
U.S. Pat. No. 1,384,721 describes a method and apparatus for physiological response analysis.
U.S. Pat. No. 3,855,416 to fuller describes a method and apparatus for phonation Analysis leading to valid truth/lie decisions by fundamental speech-energy weighted vibrato component assessment.
U.S. Pat. No. 3,855,417 to fuller describes a method and apparatus for phonation Analysis leading to valid truth/lie decisions by spectral energy comparison.
U.S. Pat. No. 3,855,418 to fuller describes a method and apparatus for phonation Analysis leading to valid truth/lie decisions by vibrato component assessment.
The disclosures of all publications mentioned in the specification and of publications cited therein are hereby incorporated by reference.